In order to reveal the relationship between the radial growth of Pinus tabuliformis plantations and the drought in the Loess Plateau,we took 30 sample plots of Pinus tabuliformis in Wuqi,Zhidan,and Yanchuan counties as the research object,and obtained the ground meteorological observation data of daily precipitation from 1961 to 2012 from 72 weather stations in and around Loess Plateau.We took the number of consecutive days without effective precipitation as a drought index,analyzed the correlation between ...